Carbon Sequestration in the Southwestern United States: Using the 'String of Pearls' Model for Cost and Source-to-Sink Assessments.

This paper describes an Integrated Assessment analytical model used by the Southwest Regional Partnership on Carbon Sequestration (SWP) to assess up to hundreds of CO 2 source and geological sink sequestration projects in the Southwestern United States. The model was first developed as a central presentation tool, later into an integrated assessment source-to-sink matching tool (based on the ‘String of Pearls’ framework), and continues to evolve to give regional summaries for large-scale carbon sequestration potential cost and performance metrics. The model’s development is part of the larger Southwest Regional Partnership on Carbon Sequestration consisting of over 20 organizations, including geological surveys, national labs, federal and state agencies, and is one of seven such partnerships organized by the National Energy Technology Laboratory. The Integrated Assessment (IA) model development team at Sandia National Laboratories continues to expand and refine the model as the larger project continues to include additional source and sink data, technology assessments, and looks to employ increasingly standardized cost metrics. Additionally, the model is able to help decision makers (e.g., policy analysts and interested energy companies) determine where a CO 2 source (e.g., power plant) could be built given a set of planning constraints based on current power plant locations, sink availability, and existing pipeline infrastructure right-of-ways. The working results indicate that the cost of capturing carbon dioxide is by far the majority of a potential project’s overall capital cost. For example, the capture, transportation and storage-associated cost breakdown of a plant in northern New Mexico may be 95%, 2% and 3% of the initial cost estimate, respectively. The IA also develops overarching results such as regional CO 2 sequestration totals, relative cost issues, and sink lifetimes across an initial fiftyyear time horizon. The initial results indicate the region may support anywhere from several decades to over ten thousand years’ worth of CO 2 sequestration potential capacity depending upon the assumptions regarding CO 2 source and sink resources. To sequester this much CO 2, however, may have substantial parasitic energy penalties ranging from 15 to 40% associated with capturing the CO 2 from, for example, power plants. The IA team, as part of the larger SWP, continues to include additional and more refined capture cost data from a larger working group across all of the regional partnerships in an effort to develop a more ‘seamless story’ for carbon sequestration at a high level. These standardization efforts also allow for common technological progress to be included in the partnership’s modeling efforts to address the cost and energy penalty issues. Ultimately, however, many of the costs will be highly site-specific for power plant-scale carbon sequestration projects. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000. SAND2007-5153C